Industrial Fire Journal - Fire & Rescue - Hemming Group Ltd
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Optimization of Smoke Management System in Short
Published:  19 April, 2010

Efficiency of smoke management system in short (up to 300 m) tunnels was evaluated by CFD simulation of typical two-way railway tunnel using FDS5 software developed by NIST, USA. In the framework of the present study we identified the worst-case scenario for fire accident in short tunnel; determined HRR curve development versus time; designated parameters for fire simulation depending on flammable materials; provided sensitivity analysis of a numerical solution optimizing the mesh size close to the fire source and in the other areas of researched tunnel; proposed different alternative smoke evacuation methods as follows: (1) natural, (2) non-mechanical with chimneys (cut-and-cover tunnels only), (3) non-mechanical with improved portals geometry, (4) non-mechanical with division of the tunnel volume by top and bottom spaces, and (5) mechanical using jet fans; optimized and performed feasibility study for each of these methods. Our analysis demonstrates that non-mechanical ventilation with chimneys would be the most cost-effective, while the best smoke management may be achieved by tunnel space division. Improving portal geometry allows significant increase of the time period satisfying appropriate standards tenable criteria requirements.